1. Field of the Invention
This invention is in the field of trusses used to support a variety of appliances, such as lights.
2. Description of the Prior Art
Various staging systems are used in the production and managing of events for every shape and size including all types of entertainment, such as, concerts, dance, theatre, comedy, etc. Typically, large scale truss assemblies support, above the staging area, various appliances including lighting fixtures used during the performance.
A minimum amount of time is allocated to the erection of staging systems since access to a performance site is limited. Thus, the truss must arrive at the performance site in a condition ready to be hoisted into place.
Trusses are transported to the performance site in the assembled state thereby requiring a relatively large amount of storage space within the transportation vehicle due to the size of each truss. A typical truss used in staging systems is approximately 36 inches wide and 42 inches in length. Some of the prior trusses have been designed to partially minimize the amount of space occupied by the truss in the transportation vehicle by allowing one side of the truss to move not only toward the other side of the truss, but also along its length since the cross members linking the truss side are not flexible and pivot on each side in the direction of the longitudinal axis of the truss. The result is a decrease in the width of the truss occupied in the storage vehicle; however, the length of the truss dramatically increases requiring large storage space. Disclosed herein is a foldable truss allowing the truss sides to move toward each other while the truss sides do not move in the direction of the longitudinal axis of the truss. Thus, the space in the transportation vehicle occupied by the truss is minimized since the width of the truss is decreased while the length of the truss remains constant. An example of a column or girder wherein the length increases as the column or girder is folded to a storage condition is disclosed in U.S. Pat. No. 1,141,385 issued to J. O. Ellinger. An example of two members moving toward each other while also moving along the longitudinal axis of the assembly by disassembly of diagonal cross supports extending between the two members is disclosed in U.S. Pat. No. 4,790,113 issued to R. K. Gregory.
A variety of products include a plurality of rod shaped members connected together by cross members removably mounted by means of conventional fasteners, such as bolts and nuts. For example, in U.S. Pat. No. 4,541,509 issued to D'Alessio et al and U.S. Pat. No. 3,011,586 issued to J. E. Harvey, Jr., the cross members may be removed from the sides of the product. U.S. Pat. No. 2,982,379 issued to R. E. Fisher discloses a folding tower having hinged cross members connected together and secured by a slidable sleeve extending over the hinge.
What is needed is a truss that may be collapsed decreasing the truss width and maintaining the truss length without requiring all of the cross members connecting the opposite sides of the truss from being disassembled.